Appointment scheduling?
 

I've tried searching through the VB4 mods for something that would allow users to schedule appointments (or something that I could use to simulate that). The only thing I've come up with is the Form mod, using it to email people who would be taking the appointments & using a custom php field to possibly inject an appointment into the calendar.

Does anyone know of a better solution?

You can use an external PHP appointment system and then just add the vbulletin header and footer for vbulletin for integration. None of them are made for vbulletin so they do not use the vbulletin calendar system, but in my opinion that can be a plus. Modifying the calendar/event system can get a bit tricky.

Anyway, maybe it is a starting point for you. :)